Today is Marimo Day in Japan. What's a marimo? Here's a hint: they look like this. As you can see, they're balls of algae that roll around the bottom of Lake Akan in Hokkaido.

The official Japanese Lake Akan homepage even has a marimo mascot. His blue-and-white getup is a cartoonified version of traditional Ainu clothing, and he's playing a kind of jaw harp called a mukkuri.

Here's a neat picture of a marimo and... maybe a marimo spirit? I don't even know. But neat.